January 1 1964 First ever Top of the Pops is broadcast from Manchester, after a merciful name-change from the suggested "Teen and Twenty Record Club". It goes out at 6.30pm on a Wednesday, and sets the format which would be followed, with more or less tinkering, until this week: artists "performing" (this would prove one of the most flexible variables) in front of a live, young studio audience, culminating in a countdown of the week's singles chart. Acts include The Rolling Stones and Dusty Springfield, with a filmed contribution from the week's number one act, The Beatles, with I Want to Hold Your Hand. Presiding: Mr (later Sir) Jimmy Saville, DJ. In those days it had to be on BBC1; the second public station didn't open until April the same year.

1967 The show moves to London, to make it easier to get acts into the studio. The BBC's new youth radio station, Radio 1, forms strong links with the show from the outset, with star DJs such as Kenny Everett presenting. One legendary performance saw Jimi Hendrix miming Purple Haze while an Alan Price record played over the PA.

1968 Pan's People, a dance troupe used to fill the stage when that week's charting acts were not available, make their first appearance. They are not the first set of go-go dancers, but they are the most memorable, staying with the show for 10 years. Their versatility is legendary, even coping when having to cover for The Clash.

1972 The distinctive TOTP theme tune - a version of Led Zeppelin's Whole Lotta Love - gets its first outing. Various other theme tunes and logos would be introduced over the years, but Whole Lotta Love remained the chart countdown backing for many years, and was reintroduced as part of a back-to-basics rework in 1998.

1973 The programme moves to Friday, briefly, but swaps back to Thursday after a ratings collapse. Future generations of TOTP producers will blithely ignore this elementary lesson from history at their peril. At the 500th show, Cliff Richard's performance is met with a mysterious shower of wigs. The Who's entourage - apparently not Cliff fans - had raided the props department.

1979 TOTP's finest hour, with viewing figures of 19 million. A strike over at ITV helps.

1981 In New Jersey, USA, MTV is born. The impact isn't immediately felt in the British isles, but it's the beginning of a process which will make TOTP if not obsolete, then at least no longer indispensable - as round-the-clock cable channels showing pop videos, and later the internet, mean that TOTP's weekly chart injection is increasingly available on demand.

1991 Producers admit - as most people have known all along - that acts usually mime, but promise that from now on the vocal track at least will be live. Other musicians continue to mime wilfully badly.

1994 Britpop should have been giving TOTP a shot in the arm, but all is not well. The beginning of the end is signalled by the introduction of TOTP2, a BBC nostalgiafest of old TOTP footage shown occasionally on BBC2. Presumably, this is meant to be a celebration of the long and rich heritage of the show. With hindsight, it looks increasingly like an unwitting admission that the only people who care about TOTP by now are over-25s hankering for the show's glory days. TOTP2 starts to spread across the schedules like a rash - by 2002 it has two weekly showings.

1996 The programme moves definitively to Friday evening, when self-respecting young people are out dancing and so on, rather than watching television. Inexplicably, this move fails to propel the show to new heights.

2003 TOTP goes out on the World Service for the first time. A major relaunch in December, masterminded by former presenter Andi Peters, aims to boost "editorial content" and initially boosts figures, but they quickly start to slide. Meanwhile, miming is acceptable once more.

2004 By May, the relaunched show is attracting just 2.6 million viewers, from 5.5 million for the relaunch special six months before. In November, the BBC announces that the show is leaving BBC1 for BBC2, in a Sunday night slot to move it nearer to the radio chart show, which now includes charts for downloads. While the chart show moves forward, there's still a suspicion that TOTP is moving towards an older audience, with the admission it will "combine some of the elements of TOTP2".